code: def apply_data_types(self, g, data_types):
      for node in nx.topological_sort(g):
          g.nodes()[node]["variable_type"] = data_types[node]
      return g
  
file_path: dowhy/dowhy/do_samplers/mcmc_sampler.py
imports: from typing import List
  import networkx
  import numpy
  import pymc3
  from dowhy import EstimandType
  from dowhy.do_sampler import DoSampler
label_desc: Use image node_id 2 for calling the McmcSampler obj's underlying member method code with example usage: obj.apply_data_types(g, data_types) and returns: g